A motorboat accelerates uniformly from a velocity of 6.5 m/s to the west to a velocity of 1.5 m/s to the west. If its acceleration was 2.7 m/s2 to the east, how far did it travel during the acceleration? I have to find: t, Vf, Vi, a, and Δx using one of the following formulas:
Vf = Vi + a*t
Vf2 = Vi2 + 2aΔx
Δx = ½(vf + vi)t
Δx= Vi*t + 1/2a*t^2

Which formula do I use? How do I solve this?

Which of the following changes will result in a stronger electromagnet? a. using fewer coils of wire b. using a higher voltage c. using a shorter nail d. using a longer wire

The coulomb's law explains which of the following? select all the force between two charged objects is inversely proportional to the charge on each object. the force between two charged objects is directly proportional to the charge on each object. the force between two charged objects is directly proportional to the distance separating them. the force between two charged objects is inversely proportional to the square of the distance separat coulomb's law is similar to newton's 2nd law. if the force between two objects is f and the charge on both objects is doubled, the new force between the would now be 2f. if the force between two objects is 2f and the distance separating them is doubled, the new force between the objects would now o the be zf.

This is for my 8th grade science class, i really don’t understand. can someone me? , lol.